D. Lejeune

Clinical trials of antidepressants: the hidden face: where locus of control appears to play a key role in depression outcome

It remains difficult to determine in what measure improvements observed in clinical trials of antidepressants may be attributable to the psychological predispositions of the subjects. The present article focuses on the effect of a psychological variable, the Health Locus of Control, which measures the extent of a subjects belief that he is in control over his own health. The hypothesis is that depressed subjects whose locus of control is internal, i.e. who perceive themselves to be in control, rather than external, i.e. control perceived as being in others or just chance, will improve more markedly and consistently on the Hamilton Depression Rating Scale, across a number of clinical trials. Forty-nine depressive patients undergoing treatment with four different compounds were included, after a weeks placebo run-in period, in a classical 42-day follow-up study comprising visits on days −7, 0, 10, 21; and 42. Interactions between the type of locus of control and the clinical course were investigated by MANOVA. Results show that with a classical design of clinical trials of antidepressants, locus of control plays a significant role if it is internal (P<0.001) in consolidating the improvement process, and that this is true irrespective of type of antidepressant. The relationship between the concept of locus of control and placebo effect is discussed.

From health locus of control to immune control: internal locus of control has a buffering effect on natural killer cell activity decrease in major depression.

Decreased immunity in depressive as compared with control subjects has been well documented, although some depressed patients have severe alterations whereas others have milder ones or not at all. Since for equal severities of depression, there may be individual differences in the degree of perceived control over ones condition, we investigated the interaction of perceived control with immunological variations. Immune function (T and B lymphocytes, lymphocyte proliferation and natural killer cell activity (NKCA)) were evaluated in 34 adult major depressives and in 18 healthy controls. Lymphocyte proliferation did not differ between the two groups, but NKCA was significantly lower in the depressed patient group. Among the depressed subjects, those who experienced less subjective control also showed significantly lower NKCA. An internal locus of control appears to act as a buffer against the decrease in cellular immunity observed in major depression. Further studies should focus on methods of coping and on degree of perceived control rather than on diagnostic and nosographic variables alone.

Hepatic [14C]aminopyrine demethylation capacity after portocaval shunting. Comparative study in patients with and without arterialization of portal vein.

The [14C]aminopyrine breath test (ABT) was used before and after surgical portocaval shunting in 29 cirrhotic patients, 15 with arterialization of the portal vein and 14 without. These two subgroups were comparable with regard to age, prothrombin time, serum albumin, serum total bilirubin concentrations, Child classification, and preoperative ABT. After portocaval shunt, a striking reduction in ABT values was observed after 6 and 12 months (90.7±8.0%,P<0.05 and 77.3±7.5%,P<0.005, respectively). No further decrease was observed between 12 and 24 months. The microsomal function was reduced to a greater extent in patients with postnecrotic cirrhosis (55±4.8%,P<0.01) than in those with alcoholic cirrhosis (84.8±10.4%,P<0.05). Arterialization of the portal stump of the portal vein did not prevent the reduction in hepatocellular function. No significant change in prothrombin time, serum albumin, or bilirubin concentrations was observed during the follow-up period in any of the groups. Overall, preoperative ABT was significantly higher in those surviving one year (0.29±0.12% administered dose) than in those who died within this time period (0.12±0.01%,P<0.005). This observation suggests that portocaval anastomosis induces an early decrease in microsomal function that is not prevented by arterialization of the portal vein. It also suggests that ABT might be helpful in selecting patients for shunt surgery.